Triadenum tubulosum (Walt.) Gleason

Locations ofTriadenum tubulosum (Walt.) Gleason in Virginia

Show image with county labels


Botanical Name
Triadenum tubulosum (Walt.) Gleason
Common Name
Lesser Marsh St. John's-wort
Hypericum tubulosum Walter
Flora of Virginia Name/Status
Triadenum tubulosum (Walt.) Gleason
This species can be readily distinguished from its similar congeners Hypericum virginicum and H. walteri by the lack of punctate glands on its foliage.

The proper disposition of plants in the genus Triadenum may be still unresolved, as they have been variously treated in both Hypericum and Triadenum by recent taxonomists. Based on a comprehensive phylogenetic study of Hypericum (sensu lato), Nürk et al. (2013, Molec. Phylogen. & Evol. 66: 1-16) included Triadenum in Hypericum, but the position of Triadenum as a somewhat basal clade and the inclusion of Triadenum japonicum suggests that the fairly ancient, e. U.S.-e. Asian vicariance had elements that were clearly similar to one another and distinct from other Hypericums long ago. The morphological distinctions of Triadenum lend further credence to its treatment as a separate genus.
Floodplain forests and swamps, usually in seasonally flooded sloughs and depressions. Infrequent to rare in the Coastal Plain and outer Piedmont, mostly south of the James River.
Native Status

To save this map, right-click (control-click for Mac users) on the map and choose "Save Image As...".